The evolution of the web has brought content submissions to the forefront of public online services. User submissions including comments, status updates, images, and the like are now commonplace in virtually all public online services, including social networking sites, online news articles, and blogs. A vast majority of material is now provided by end-users rather than webmasters. As a webmaster, one has the ability to modify or remove content at will, or to reserve access to a select community of viewers. An end-user user posting into a web service, however, normally gives up all these rights as soon as the content is uploaded.
Users of a public online service who share content on the site can create serious risks to their own privacy. Not only do social networking site users face privacy concerns with respect to the social network site itself having access to, and possibly ownership of, content posted by its users, but third party applications and advertisers integrated/linked into the social networking site may also have access to such content. Social networking site APIs can allow integration of third-party software and give third-party developers access to user data. While these open interfaces enable site enhancements, there is an important privacy trade off, which many site users do not appreciate. Thus, social networking sites can pose serious privacy risks to their users by exposing user data to third-party developers and advertisers. To allay fears of privacy violations, some social networking sites provide users with some access control settings to place restrictions on who may view their personal information. The introduction of open APIs to social networks, however, enables such access control preferences to be circumvented, thus making user data vulnerable to data mining and other privacy issues.